There's a neat book about America and the hog business, "Hog Ties", by Richard P. Horwitz.
Although Dr. Horwitz is a professor of American studies, he moonlighted on a hog/cattle/grain farm for 20 years.
I agree with this review of the first edition of the book at Amazon:
Dr. Horwitz points out a lot of things that most pork eaters don't know. One of the biggest mistakes that people can make is to assume that hogs are just like humans:
It is a very thoughtful look at American culture through the porthole of the relationship of people to pigs.
Many people have commented on the plight of "family farmers" as affected by "integrated" agriculture, but they either have a political agenda or little real understanding. In this case, tremendous effort is made by the author to understand the business of pigs and pork, and changes in society and the pig industry. This description of the swine industry is a studied, objective viewpoint, even if it is incidental to the real purpose of the book.
Mainly, the book is a unique study of human beings and relationships to each other and other species, including pathogens. The book contains thought-provoking observations on life, death, culture, agriculture, multiculture, and communication.
Hogs present and additional challenge in that they plainly are different enough from people that projections of the "if-I-were-one" sort are a radical stretch. Try as I might, for example, I cannot fully imagine being drawn to the smell of shit or engaging in other grossities that pigs normally elect when given a chance. Like most people who sing the song, I can more readily imagine "swinging on a star." But perhaps hogs under extreme conditions put out such clear signals that wholesale leaps of imagination are not required. The challenge might be a bit of translation rather than projection.Google Books allows you to preview the book.
When, for instance, you walk into any swine barn, you are bound to see hogs chomping on the steel bars of their pens. Scrunch, scrunch, grunt, scrunch, over and over again. What does this "chewing behavior" mean? What does it tell us about, say, the animal's welfare or respect for its rights?
The Humane Farming Association, claiming support from "agricultural scientists" who study such things, says they know. Chewing is a "temporary measure of releief from the torment of crate confinement." It is "abnormal ...simply the desperate expression of frustrated animals pushed ot the point of madness ...[that] resembles, in many respects, the development in humans of chronic psychiatric disorders."
Since I am neither an animal scientist nor a psychiatrist, I may be handicapped here, but this is not the sort of interpretation that experience seems to counsel. I regularly see hogs (and "cribbing" horses) engage in such "endorphin-releasing stereotypes" in wide-open fields. Although the sows on the old-timey farm next-door have about a quarter-acre apiece to roam around, they ordinarily crowd together ("cheeck-to-jowl," as people have been saying for decades before confinement was an issue) and chomp on the panels in one corner. Chewing on gates is a common enough pastime to suggest an analogy closer to biting your nails than banging your head against a wall.
I could understand why Bay Area vegetarians might leap to alarming conclusions, but I find it hard to believe that people who well know pigs would respond in kind. In fact, I was unable to find the "agricultural scientists" to whom the Humane Farming Association referred. The association's director would not respond to my telephone calls and letters requesting citations. In searching for those citations, what I found instead was strong support for my common sense. John McGlone, probably the single most respected pig specialist among animal behaviorists in the United States, monitored a controlled comparison at his research center at Texas Tech University and concluded: "Outdoor sows spend as much time chewing rock and chewing in the air as indoor sows spend chewing bars... We conclude from our studies that both behaviors are normal."